Melissa Moore's parents, Rose Hucke and Keith Jesperson, were married in 1975. "When you're young, you don't realize that this person's going to become who they become," Hucke told "20/20" in a 2010 interview. "At the time he was a very charismatic, considerate young man and I had no clue that this is what he would become."

Keith Jesperson holding daughter Melissa when she was a baby. Melissa was in high school when her father, a long-haul truck driver, was charged with multiple murders. Now in prison for life, Jesperson told "20/20" in 2010 that he loved his three children very much and always will.

Melissa, 2, on the couch with her dad, Keith Jesperson. She said he would blow into town and lavish them with gifts and then depart again, leaving her mother to take care of the three children.

Melissa, 8, standing in her First Communion dress with her parents and younger sister. Melissa's parents would eventually get divorced, but she says Jesperson visited the family whenever his trucking jobs took him their way. "He would come into town and the first thing he would do is take us out to eat," Moore told "20/20" in a 2010 interview. "Then after going out to eat, he would say, 'Well, let's go shopping,' and then after shopping he would take us to the grocery store and then he would stay the night and leave the next morning."

Melissa and Sam Moore are seen here while they were dating. They met at a church dance in April 2000 when Melissa was 21. By then her father was in prison. "I knew that our relationship was going towards marriage ... and I thought, well, this is something he's going to need to know," Melissa told "20/20" in a 2010 interview.

Melissa Moore and her husband, Sam, cutting their wedding cake. They married in November 2000, seven months after they met. "I said, 'Hey, you know, you always ask me, you know, who my father is. I want you to know he's in prison,'" Melissa told "20/20" in a 2010 interview. "And then I said 'He's' a serial killer.' [Sam] put a face on that it didn't bother him."

Melissa and Sam Moore with their two kids, Aspen and Jake. Melissa said she used to be afraid that her son "might have characteristics or DNA" that would make him capable of "being a sociopath like my dad." She later learned that research has found there is no genetic link.

Keith Jesperson's first victim was Taunja Bennett, murdered in 1990. At first, a woman who had nothing to do with the case used information from news reports to try to frame her boyfriend for killing Bennett. But Jesperson wanted credit for his crime and left a note at a rest stop bathroom that said, "Killed Tanya [sic] Bennett in Portland... Two people got the blame... So I can kill again.”

In 2005, Melissa Moore and her husband, Sam, took their two children to visit their grandfather in the Oregon State Penitentiary in Salem. That was the last time Melissa saw her dad.

Convicted serial killer Keith Jesperson, who earned the nickname the "Happy Face Killer" for the smiley face drawings he included on his confession letters, has been serving three consecutive life sentences in Oregon since 1995.

Melissa Moore, now 36, said she has become a kind of advocate for relatives of mass murderers and speaks out on their behalf. She wrote a book called "Shattered Silence." Moore said she has spoken with over 100 children of murderers and has a new TV series on LMN called, "Monster in my Family." "Meeting family members of ... other serial killers… I know that that's my meaning," she told "20/20" recently. "Not because of but despite of what happened to me, we are finding meaning together in the aftermath of these horrible crimes."